Traditionally, system administrators have used the iostat utility
to track the amount of io performed to a local disk filesystem.
Similar functionality is provided for NFS mounts via the nfsstat
utility that reads the NFS client's stats from /proc/pid/mountstats.
There is currently no good way for a system administrator or a
monitoring application inside a container to track the amount of io
performed via overlayfs.
Opt-in for generic io stats via /proc/pid/mountstats to provide
that functionality.
This feature depends on CONFIG_FS_IOSTATS.
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
fs/overlayfs/super.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 7bb0a47cb615..4a5847bca1a6 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -6,6 +6,7 @@
#include <uapi/linux/magic.h>
#include <linux/fs.h>
+#include <linux/fs_iostats.h>
#include <linux/namei.h>
#include <linux/xattr.h>
#include <linux/mount.h>
@@ -2165,7 +2166,7 @@ static struct dentry *ovl_mount(struct file_system_type *fs_type, int flags,
static struct file_system_type ovl_fs_type = {
.owner = THIS_MODULE,
.name = "overlay",
- .fs_flags = FS_USERNS_MOUNT,
+ .fs_flags = FS_USERNS_MOUNT | FS_SB_IOSTATS,
.mount = ovl_mount,
.kill_sb = kill_anon_super,
};
--
2.25.1
